166 



DR. P. CHALMERS MITCHELL ON THE 



[May 16, 



inserted to the femur along a narrow vertical line. In Vanellus 

 the caudal portion is very large, whilst the accessory portion is 

 present, but minute and with a tendinous degeneration similar 

 to that just described. In Thinocorus, Hydrojyhasiainis, and 

 Rhynchcea both portions are present and large. In Glareola, 

 Charadrius, and Himcmtopus the caudal portion is large, and the 

 iliac is extremely minvite, represented by not more than a few 

 fibres. In Gallinago and ^colopax the caudal portion is of 

 modei-ate size, the iliac portion completely absent. 



Text-fig. 2^ 



^(0 



ud.il.fl. 



L FIB (2) 



Thig-li-muscles of Chionis alha. Eight thigh, external view. 



IL.TR.E., P., M., A. llio-ti'ochanterici extenius, posterior, medius et anterior. 

 IL.FIB. (1). Origin of ilio-fibularis sen biceps, cut and reflected. IL.FIB. (2). 

 Insertion of biceps, cut and reflected. I.F. Ischio-femoralis, sen obdurator 

 externus. CAUD.IL.F. 1, 2. Insertions of caud-ilio-femoralis (accessory femoro- ' 

 caudal (1) and femoro-caudal (2)). CAUD.IL.FL. Caud-ilio-flexorius, cut, and 

 origin reflected. IS.FL. Ischio-fiexorins. P. I.F. Pnb-ischio-femorales, seu 

 adductores long-us et niagnus. The tendinous areas are dotted. X. Tendinous 

 area on accessory femoro-caudal. F.T.E. Femoro-tibialis externus. 



(Edicnemus in this respect, as in others, shows its wide diver- 

 gence from the typical Limicoline condition. Of the others, 

 Thinocorus, Hydrojjhasianus, and Rhynchcea show what is probably 

 the archecentric or generalised condition for birds, the j)resence 

 of both muscles in a well-marked form. The remaining biixls of 

 the list show that the tendency of modification in the group is for 

 the disappearance of the iliac portion (the " accessor}- " of Garrod) ; 

 and complete disappearance has been reached by Gallinago 

 and Scolopax., two bii'ds in other respects relatively highly 

 specialised. 



Gaud-ilio-Jlexorius {Semitendinos%i,s anul Accessory semitendi- 

 Qiosus), Ischio-^exorius (text-fig. 28). — In all these biixls the three 



